A 14-year-old boy presented with intermittent, terminal, gross hematuria over a 6-month period; each episode lasted of 3-4 days. The boy had no notable medical history and did not smoke. Because he was healthy without previous medical and surgical problems, he did not initially tell his parents about this symptom. When examined in the outpatient clinic, his vital signs were within normal limits, he was uncircumcised, and had no specific clinical findings. Apart from hematuria evident on urinalysis, there were no abnormal laboratory findings. Urine cytology showed no evidence of malignancy. We found a 2-cm papillary mass around the bladder neck while performing preoperative outpatient cystoscopy with a 6.5-mm flexible cystoscope (CYF-VHS, Aizu Olympus Co., Aizuwakamatsu, Japan) that day (Fig. 1). There were no specific upper urinary tract findings on abdomen-pelvic computed tomography (Fig. 2). Transurethral resection of the bladder mass under general anesthesia was performed using a 22-Fr bipolar resectoscope (Richard Wolf GmbH, Knittlingen, Germany). A single 2-cm papillary mass with a stalk was found positioned at 12 o'clock. There were no abnormal findings in other areas of bladder including at both ureteral orifices. Hematoxylin and eosin stain of the resected lesion revealed a noninvasive, high grade urothelial carcinoma (papillary transitional cell carcinoma, grade 2/3, pTa). At high magnification, a solid papillary core and disordered, thick urothelial proliferation with irregular pleomorphic nuclei of varying sizes were seen (Fig. 3). Flexible cystoscopy was performed 3 monthly, and postoperative adjuvant intravesical bacillus Calmette-Guerin (BCG) instillation therapy was administrated on six occasions. At present, 9 months after undergoing transurethral resection surgery, there is no evidence of recurrence or metastasis (Fig. 4).

Urothelial or transitional cell carcinoma is distinctly rarer in children than in the elderly. Multiple risk factors for urothelial carcinoma in adults have been identified, including smoking, occupational exposure to aniline dyes, phenacetin and low fluid intake [4,5]. However in children, these risk factors are somewhat questionable.

In Europe and United States, bladder cancer accounts for 5%-10% of all malignancies in adults but is highly unusual in children. An incidence of 0.4% in the first 2 decades of life was reported in a study by Javadpour and Mostofi (quoted from [1]). Papaillary urothelial carcinoma with low malignant potential is reported to recur but not to progress. However, low grade and, to a greater extent, high grade urothelial carcinomas do show progression and may result in death. The majority of pediatric urothelial carcinoma (78.3%) are noninvasive with low malignant potential; 13% are high grade. The recurrence rate is about 14% (3 of 21 patients) over a mean follow-up duration of 4.5 years [6]. Treatment of these young patients includes transurethral resection surgery or partial cystectomy (the latter reported in 1 case).

The most common symptom in bladder urothelial carcinoma is painless gross hematuria, symptoms of bladder irritability are uncommon. About 75% of bladder urothelial carcinomas in children are located in the trigone [6].: most of lesions are solitary papillary carcinomas with low malignant potential. There is a 50%-60% recurrence rate after initial excision with a 10%-15% of progression to muscular involvement in adults. However recurrence or progression during follow-up is uncommon in patients ＜20 years old, recurrence rate in this age group is reported to be 7% [7]. Furthermore, because papillary urothelial carcinoma with low malignant potential is most commonly found in younger patients, the rate of progression to higher grade and stage is likely to be low [6].

The treatment of choice in localized, low-grade bladder urothelial carcinoma is transurethral resection of the lesion without adjuvant intravesical instillation treatment [6]. Surveillance has shown that adjuvant treatment after complete transurethral resection of bladder lesion is not necessary in pediatric and adolescent patients because urothelial carcinoma in this age group tends to be histologically low-grade, and exhibits a lesser tendency than in older patients to recur and progress [3].

However, in the present case, the lesion was positioned in an uncommon site that made complete resection difficult (above bladder neck) and was, reported to be a high-grade papillary urothelial carcinoma. Hence, we decided to administer adjuvant intravesical instillation of BCG and to maintain close surveillance. In reviewing the literature, ultrasonography was noted to be extremely effective in identifying bladder tumors [8]. Although rigid cystoscopy is invasive diagnostic tool, flexible cystoscopic examination is more comfortable and acceptable for adolescents because flexible cystoscopy is more compliant, and has a smaller diameter than a rigid cystoscope. If a young patient with bladder carcinoma is able to tolerate it, flexible cystoscopy under local anesthesia is worth trying.

There is no standard surveillance method or protocol for pediatric and adolescent patients with bladder carcinoma. Although extremely rare, some cases of recurrence and death have been reported [9]. Urologists must remember that young patients with bladder urothelial carcinoma should be periodically screened for recurrence to ensure timely identification of recurrence or metastasis [10]. In addition to postoperative adjuvant intravesical instillation therapy, close follow-up studies (periodic computed tomography, and 3 monthly flexible cystoscopy) are needed if the patient has a high-grade urothelial carcinoma.